Design of equipment in the semiconductor industry (e.g., tools such as plasma etchers and CVD deposition reactors) typically begins with a customer""s performance specification, such as a particular etch rate and uniformity for a particular material, and then applies experience plus physical models to create a design to meet this specification. Perturbations of the initial design follow if the initial design fails to meet the specification.
This approach has problems for the customer, including the all-to-often changes in the desired specification during or after the design work.
The present invention provides a design and evaluation method which replaces the tool specification with a requirements region plus associated evaluation functions defined on the requirements region; the evaluation method employs the evaluation functions and the design method uses the evaluation in an iterative feedback design.
This has advantages including an evaluation and design which accommodates specification changes.